#include<stdio.h>  
#include<stdlib.h>  
char* strcat(char *str1, char *str2)  
{  
  
    char *p; 
	p=(char*)malloc(60);
	p=str1;
    while (*str1)  
    {  
        str1++;  
    }  
    while (*str1++ = *str2++)  
    {  
        ;  
    }  
    return p;  
}  
  
  
int main()  
{  
    char arr1[20] = "hello ";  
    char arr2[20] = "world!";   
    printf("%s", strcat(arr1, arr2));    
    return 0;  
} 
